Question: Simplify the expression. $(3a^{4}-6a^{2}-5a)(-4a)$
Explanation: First use the distributive property. $ 3 a^4 (-4 a) - 6 a^2 (-4 a) - 5 a (-4 a) $ Simplify. $-12a^{5}+24a^{3}+20a^{2}$